Pressure-governed circuit controller



May 1, 192s. 18,667,914

R. E, WHITE PRESSURE GOVERNED CIRCUIT CONTROLLER Filed Jan. 29, 1925 Patented May l, 1928'.

e .Imran rx'lvm.

RAYMOND WHITE, OF CHCAGO PRESSURE BOELER CG., F 015:1..

ILLINOS, ASSIGNR T0 "WINSLUW SAFETY HIGH LGG, 11314131015, A CCY.

PRESSURE-GOVERNED OIRCUET CONTROLLER.

Application filed January 29, 1923.

The present invention relates to pressure governed circuit controllers.

The present circuit controller has been developed for the regulation of atomizing burners of the class described in the copending application of myself and Charles L. Page, Serial No. 611,827', iiled Jan. 8, 1923, and in the copending application of mysell:l and Kenneth C. -Brown, Serial No. 616,912, tiled Feb. 1928. The burners illustrated in the above applications have been designed for automotive work, such as the heating oi' high pressure steam boilers for the propulsion ot pleasure cars, buses, trucks, and tractors. lThe control of these burners is largely, it not entirely, automatic-generally in accorda-nce with the pressure of the steam in the boiler. The necessity for reliable burner operation is so essential to the commerical success of these steam vehicles that the requirements for the pressure governed circuit controller are very exacting, and the operation of these devices must be practically infallible.

In the following description I have disclosed an automatic circuit controller embodying a combination and arrangement of contacts and actuating parts which have given remarkable service tor a long period of time in the actual control of burners ot' the above types. I refer to these burners merely for the purpose of illustrating an exemplary situation, and not with the intention ot limiting the application ot my improved circuit controller thereto.

In the accompanying` drawing, the ligure is a diagrammatic sectional elevation illustrating a preferred embodiment of my invention, the improved circuit controller is designated 1 in its entirety7 and the boiler, illustrated fragmentarily, designated 2. The circuit controller 1 controls the primary circuit of a relay 3, which in turn controls the main circuit or' an electric motor 4l, which drives the blower 5 for the atomizing burner.

The circuit controller 1 comprises an upper casting 7, in which is housed the compression spring and diaphragm, and a lower casting 8, in which is housed the contact mechanism. The two body members 7 and 8 are adjustable relative to each other for the purpose of adjusting the device to cut out at different pressures. The casting 7 comprises an upper cylindrical housing 9 having an upper flange 11 :tor receiving the Serial No. 615,774.

cover 12. A diaphragm 18 ot suitable material to withstand the high temperatures and pressures is clamped between the cover 12 and the flange 11 by screws 14 which pass down through holes in the cover 12 and cap into the flange 11. A gasket (not shown) may be interposed between the cover 12 and flange 11 to me ain a tight joint between these opposing surfaces and to obtain a mechanical pressure upon the peripheral edge of the diaphragm 13. A steam pipe V16 leads from a boss 17 on the cover 12 to the boiler 2, the connection thereto being represented diagrammatically by the union' 18. ln the vehicle in which the present circuit controller has been used, this boiler generates pressures ranging from 800 to 1500 pounds. vertical operatingrod 19 entiers the lower end ot the housing 9 axially and, eX- tending up into the upper end of the housing, threads into the hub of a collar 21 which bears against the under side ot the diaphragm A shift compression spring 22 in the housing 9 bears against this collar 21 to oppose the steam pressure impressed on the other side ot the diaphragm 18, this end ol" the spring being centered by the hub on the under side ot the collar 21. The lower end of the spring 22 rests on a flanged colla-r 23 which has a spherical recess in its under side centering over a spherical end of a bushing 2Liscrewing up into the bottom of the housing 9. rThe lower end of the bushing 24 has a plurality ot radial sockets -25 by which the bushing can be turned between the depending spider arms 26 for increasing or decreasing the pressure of the spring 22. The lower ends or" the spider arms 26 are formed integral with an axial boss 27 which is internally threaded for the reception of the threaded neck 28 extending upwardly from the casting 8. The operating rod or 1 1 passes down through the bushing 24 shaft 1,/ and through a bore in the threaded neck 28. A check nut 29 sere-.vs over the neck 28 and locks the latter in any position to which it may have been adjusted in the boss 27.

The lower member 8 is constructed in the form of a cap 81 having a depending annular i'iange 82 in which is seated a ring 33 of insulating material, such as libre. A cylindrical glass shell or housing Sfr abuts at its upper end in an annular recess in the under side of this libre ring 38 and is supported at its lower end in a ring 85 which encircles the outside of the glass tube. The ring 35 is joined to the cap 31 by two side members 36 extending downwardly from the flange 32. A cap 37 screws over the outside of the ring 35 and compresses a pliable washer 38 up against the bottom of the glass shell 34 for resiliently forcing the latter up lagainst the insulating ring 33 and for maintaining an oil tight joint at the bottom of the glass shell. inside the glass tube 34 is another short section of glass tubing 39 which rests on the 'washer 33, and which forms at its upper edge an abutment stop 41 for separating the electrical contacts in a manner which I shall now describe.

The lower end of the operating rod 19 enters the glass shell 34 and passes down through an insulating sleeve 42 of fibre or other suitable material. The lower end of this operating rod is reduced or threaded to provide va shoulder against which is held a contact washer or ring 43. A nut 44 screws over the lower threaded end of the operating rod 19 and holds the Contact collar 43 against the aforesaid shoulder. The collar 43 is, of course, in grounded relation with the operating rod 19 and constitutes one contact member of the circuit interrupting means. of an annular flanged ring 45 which is carried on the lower end of the insulating sleeve 42. This insulating sleeve has a free sliding fit on the operating rod 19. The contact collar 43 is of slightly larger diameter than the internal diameter of the contact ring 45 so that an annular contact is obtained between the collar 43 and ring 45,. The contact ring 45 normally tends to seat on the abutment shoulder 41 at the top of the glass tube 39, being normally thrust downwardly vtoward this shoulder by a spring 46 kwhich bears against the upper side of the contact ring. rThe upper end of this spring bears against a metallic washer 47 which may be held against the under side of the insulating ring 33 by the spring pressure, or which may be suitablyy secured thereto. The cap 31 is formed with a laterally extending arm 48 for supporting a binding post 49. This binding post may consist of an ordinary screw suitably insulated from the arm 48 by insulating washers and a bushing. A wire 51 leads from the binding post 49 in through an aperture in the ring 33 and extends downwardly through said ring for suitable connection with the metallic washer 47. The binding post 49 constitutes one terminal for connection with the outside circuit, this side of the circuit being thereby connected through wire 51 and metallic washer 47 to the spring 46. The lower end of this spring is in contact with the contact ring 45 so that the circuit is thereby completed to this ring. The other side of the circuit is suitably grounded to either of the The other contact member consists y castings 7 or 8, such as through the connector clip 53 engaging under the head of the screw 14. This places the operating rod 19 in grounded relation with the casting 7 through the metallic diaphragm 13 and the various other points of Contact with the operating rod. Thus the contact collar 43 is connected to the other side of the circuit. The two contacts may be submerged in oil 54. This oil may be introduced through the aperture 55 in cap 31, and may be drained through the lower port 56 which is normally closed by the removable plug 57. The operation of the circuit controller is as follows:

`When the boiler pressure is below that predetermined pressure at which the burner operation is to be cut off, the diaphragm 13 stands comparatively high under' the pressure of the spring 22, with the contact ring 45 elevated abovethe shoulder 41. 1n this position of the diaphragm the contact ring 45 is forced down upon the upper edge of the contactcollar 43l by the lower spring 46. This constant spring pressure between these two contact members insures uniformity and continuity of contact with a minimum resistance through the actual contacting surfaces. The two contact members float together with the up and down movement of the operating rod, being held in contacting relation all this time under the pressure of the spring 4G. When the steam pressure reaches a predetermined maximum for which the Vdevice is set, the downward flexure of thc diaphragm 13 will bring the two contact members downwardly until the contact ring 45 seats on the abutment shoulder 41. Thereafter' continued downward movement of the operating rod will cause the contact collar 43 to drop away from the contact ring 45. This separating motion between Vthe contact members produces a positive clean break; the function or pressure of the spring being entirely nulliiied when the contact ring 45 strikes the shoulder 41 and this spring being therefore incapable of producing any hang-fire or arcing engagement between the contacts. Similarly, when the boiler pressure has reccded, the upward movement of the contact collar 43 completes the circuit quickly and cleanly after which the pressure of the spring 46 becomes effectual for maintaining the contacts in firm pressure engagement. A relatively large contacting area is afforded between the outer periphery of the contact collar' 43 and the inner peri ahery of the contact ring 45. The quenching oil 54 is not necessary for the comparatively low voltages of the average burner installation, but may be employed for higher voltages. y

Adjustment of the device for performing its cut-out function at different steam pressures is obtained either through manipulation of the threaded bushing Q4, for increasloi) ing or decreasing the spring pressure, or through longitudinal adjustment between the castings 7 and 8. This latter adjustment is performed by loosening the locl nut 29 and screwing the threaded neck 2S up or down in the lboss 27.

rIlhe two, circuit wires 6l and (Si), lead to the winding of the relay B, which relay may be mounted on the back of the instrument panel or clash of' the vehicle. Included in the circuits (Sl-GQ is a source oi low potential, such as the single cell ot a multiple cell storage battery The relay is ot any standard type, the contacts ot which control a circuit through the wires G-l and 65. This circuit (S4-65 controls the lower motor 4, and includes in series the entire group of cells of the storage battery 63. The liquid fuel is introduced into the air' stream impelled from the blower 5 from an aspirating jet, or any ,other suitable manner, such as will be obvious to those skilled in the art.

Although I have shown and described a particular embodiment of' the invention, it will be understood that I contemplate changes in torni and arrangement of parts as circiunstances suggest, or necessity requires, without depar ing from the scope of the invention as de'ned in the appended claims.

I claim :ed

l. In a circuit controller, a diaphragm responsive to iui'd pressure, a first contact member mounted to move with the said diaphragm through substantially its entire rz nge of movement, a second contact member arranged to move with the said diaphragm through only a part of its range of movement and disposed in engagement with the first contact member during the same and out of engagement dui-ino' the other part of its range of movement, a housing associated with the said contact members having a shoulder for engaging the second contact member to permit continued movement of the first contactmember out oi' engagement therewith and past the said shoulder and means for urging the said second contact member in the direction of the continued movement of the said first contact member.

2. In a device of the class described, the combination of a pressure responsive surface, an operating rod extending from said surface, a first contact adjustable on said rod, a second contact sleeved on said rod for motion relative to said first contact, and a housing comprising top and bottom portions, a rigid connection between said portions, and a transparent wall held between said top and bottom portions and having an internal wall extending part way of the length 'of the housing to form a stop and limit the movement of one contact to permit the other contact to move out of` engagement therewith.

3. In a device of the class described, the combination of a diaphragm, a rod extending from said diaphragnn a iirst contact carried by said rod, a second annular contact mounted concent-rically on said rod, an insulating sleeve mounted on the rod and receiving the second annular contact thereon, said leere being interposed between said second contact and said rod and a spring around the sleeve between a fixed part and the second Contact to act on the latter and tend lo force the same into engagement with the first contact.

In a device of the class described, the combination of a diaphragm, a rod extending to said diaphragm, an annular contact mounted on said rod, an annular ring contaw` mounted concentrically of said rod, an insulating sleeve interposed between said latter contact and said rod, a spring adapted to torce said contacts together, a housing for said contacts, and a shoulder forming partot said housing adapted to be engaged by said annular ring contact for separating said contacts by continued movement of the rst annular contact.

5. In a device of the class described, the combination of a. first housing, a diaphragm in said irst housing, a second housing, contact mechanism in said second housing, an ope lative connection extending from Said diaphragm to the contact mechanism in said second housing, and means for adjusting said housings relative to each other, said first housing having a threaded aperture in its bottom wall, a bushing adjustable in said threaded aperture, a flanged collar having engagement with the bushing, a spring between the diaphragm and flange of the collar, said bushing permitting adjustment of the tension of the spring, and additional means carried in the second housing for varying the adjustment of the contact mechamsm.

6. In a device of the class described, the combination of a first housing, a diaphragm contained therein, a second housing having supporting connection with said first housing, said second housing having a neck portion, contact mechanism in said second housing, an operating member extending from said first housing-to said second housing, and means for shifting said housings towards and away from each other, said first housing having an internally threaded boss engaging said neck portion, and a nut on the threaded neck portion to engage the boss and hold the latter in adjusted position on the neck portion.

'7. In a device of the class described, the combination of a diaphragm, an operating rod having connection with said diaphragm, a pair of contacts adapted to move with said rod through a predetermined portion of its movement in either direction, means for separating said contacts when said rod moves beyond a predetermined point, and a housing comprising a transparent Wall enclosing said contacts, said Wall including two sections, one being shorter than the other and forming a shoulder therein to limit the movement of one contact.

8. In a device of the class described, the combination of a diaphragm, an operating rod extending'therefrom, a pair of contacts associated with said rod and adapted to move therewith during its normal movement, means for separating said contacts when said rod exceeds its normal movement, and means enclosing said contacts comprising a cylindrical transparent Wall including a plurality of sections, one being disposed Within the other and forming a shoulder to limit Athe movement of one contact as part of said separating means. y

9. In a pressure governed circuit controller, the combination of a diaphragmk chamber, a diaphragm therein, one side of said diaphragm being subjected to fluid pressure, a compression spring effective againstl insulating sleeve between said ring andA said rod, a spring normally tending to force said contacts together, a shoulder adapted Yto bel engaged by said contact ring When said dian phragm is lieXed by pressures beyond a predetermined maximum, means for connecting said contact collar to one side of the circuit, means for connecting said contact ringto the other side of the circuit, and a housing enclosing said contacts for contain-` ing an arc quenching oil.

In Witness whereof, I hereunto subscribe .my name this th day of January, 1923.

RAYMOND E. WHITE. 

